The present invention concerns testing of printed circuit assemblies and pertains particularly to an interconnect adapter to a printed circuit assembly used for performing testing in an operational environment.
When producing printed circuit assembly (PCA) units, such as network interface products, some portion of the PCA units that are built inevitably do not function as desired. Often defective PCA units can be detected when tested as part of an assembly line. In some cases, however, some PCA units are best tested in an "operational environment" that is, the PCA units need to be attached to a host device and exercised in a manner as the PCA units are intended to be used.
When tested in an operational environment, the PCA unit is attached to the host device. The microprocessor which controls the PCA is typically disabled and an emulator is used during the testing. The emulator is typically attached using test clip adapters. These test clip adapters are available for fine and extra-fine pitch surface mount components.
There are several disadvantages to using the currently available conventional test clip adapters for operational testing. For example, the test clip adapters that are available for large ASICs are difficult to attach properly and are easily dislodged. In addition, the pins of the test clip adapters can get bent such that they do not make reliable connections. Also it is possible to install the test clip adapters in a wrong orientation thus resulting in incorrect connections. Additionally, existing test clip adapters are expensive.
Additionally, while conventional test clip adapters, despite their disadvantages, are functional for connection to typical ASIC packages which utilize lead frames around the peripheral of the package for connection, they cannot be used with packaging technologies such as ball-grid arrays (BGAs) which use solder balls under the ASIC package for electrical connections to a printed circuit board (PCB).